A total of 29 patients have been enrolled in the study protocol and were randomized. Nine patients in group 1, eleven patients in group 2 and nine patients in group 3. The investigators noted a significant increase in fat fraction in all three groups. The mean global increase in fat fraction was 4.35 + 5.51 (p=0.001). All the increase was achieved in the first six months of therapy or 60 u/kg dose every two weeks. In one subsequent months, at 30 u/kg the fat fraction leveled off. Calitriol supplementation had no effect on none density as an adjunct to enzyme replacement therapy. Trabecular bone density measurements and markers of bone turnover at 2 years are pending on the twentynine patients enrolled in the study. Preliminary findings suggest an increase in blood osterocalcin and urinary deoxyprindoline. Supportive of increased bone turnover.